Through-the-flowline tool installation system



5 Sheets-$heet l FIG. 5

March 14,- 1967 E. D. YETMAN THROUGH-THEFLOWLINE TOOL INSTALLATIONSYSTEM Filed Jan. 28, 1963 INVENTOR EDWARD D. YETMAN BY1 %Zg{ F l G.

HIS ATTORNEY 5 Sheets-Sheet 2 7 O 7 .l 6 5 B B 6 w w 5 6 5 I 4 K l I I Wi O 5 fl) Em u r 23 5 7 5 6 4 5 m mm mmm lm mm Fl G. 20

E. D. YETMAN FIG. 2B

INVENTORI EDWARD 0. YETMAN BYIQ 2; fig

HIS ATTORNEY March 14, 1967 THROUGH--THEFLOWLINE TOOL INSTALLATIONSYSTEM Filed Jan. 28, 1963 mml Wm? O Q l! m 5% J FIG. 2A

March 14, 1967 E. D. YETMAN 3,308,880

THROUGH-THE-FLOWLINE TOOL INSTALLATION SYSTEM Filed Jan. 28, 1963 5Sheets-Sheet Z FIG. 3 92 INVENTOR:

EDWARD D. YETMAN HIS ATTORNEY March 14, 1967 E. D. YETMAN 3,308,880

THROUGHTHE-FLOWLINE TOOL INSTALLATION SYSTEM Filed Jan. 28, 1963 5Sheets-Sheet 4 IBI FIG. 6

INVENTOR:

EDWARD D. YETMAN H IS ATTORNEY FIG. 8

March 14, 1967 E. D. YETMAN 3,308,880

THROUGH"THEFLOWLINE TOOL INSTALLATION SYSTEM Filed Jan. 28, 1963 5Sheets-Sheet 5 l y I820 &

FIG. 9A FIG. 9B

INVENTOR.

EDWARD D. YETMAN H s ATTORNEY United States Patent- 3,308,8fi9THROUGH-THE-FLOWLHNE TOOL INSTALLATION SYSTEM Edward D. Yetman, Houston,Tex., assignor to Shell Gil Company, New York, N.i., a corporation ofDelaware Filed 12.21.28, 1963, Ser. N 254,167 4 Claims. ((33. 166-5) Thepresent invention relates'to a system for running well toolsinto and outof well strings through curved conduits communicating therewith. Moreparticularly, the invention is directed to a means for installing andretrieving well tools in well strings disposed inunderwa-ter wellsthrough curved fiowlines communicating with these wells. The inventionhas specific application to the running in and retrieving of well toolsfrom well string mandrels disposed at locations inexcessible toconventional running in and retrieving apparatuses.

The invention is especially suited for the through-theflowline operationof underwater wells. Through-thefiowline operations refer to techniqueswherein well completion and operation procedures are conducted through afiowline'communicating between a surface location, such as an operatingstation, and a submerged well installation. With such techniques, asubmerged well can be equipped initially with facilities that will allowmaintenance of production via the existing closed system for the life ofthe well without the use of wire line tools or workover rigs. A primerequirement of such techniques is the ability to select and land toolsat will in any of several locations within a tubing string. The presentinvention was developed with this object in mind and has provedparticularly suitable for inserting tools, such as flow valves, in oneof a preselected series of substantially identical tool receivingpositions within a well string. The invention provides means whereby aninstallation mechanism may be pumped into and through a well string to apreselected position where it can be activated to install a tool securedthereto in place. The invention also provides means whereby a tool soinstalled can be similarly retrieved.

The invention promises to be particularly valuable in the recentunderwater completion procedures being used by the oil industry atoffshore locations. In these procedures, both the wellhead assembliesand production control units are positioned beneath the surface of thewater and preferably close to the bottom of the water. Positioningwellhead assemblies and control units in this manner has the advantagethat it does not present navigation hazards, nor is it subject to thecorrosive action of salt water spray and air, as are assembliesextending above water. In addition, positioning wellhead assemblies andproduction control units at the bottom of the ocean results inconsiderable savings, since it is not necessary to erect protectivestationary platforms around the wellheads in the manner employed toprotect well casings and wellhead assemblies extending above the surfaceof the water. assemblies on the ocean floor often becomes absolutelynecessary where depths are encountered which make it infeasible toextend structures from the floor of the ocean to the surface.

The placement of wellhead assemblies on the ocean floor has, however,presented new problems with regard to the carrying out of workover,maintenance, and other operations in completed wells. Major workoveroperations call for the use of an operating station in the form of abarge, platform or vessel positioned on the surface of the water abovethe well, together with equipment for going to and entering the wellheadassembly and any tubing and/or casing strings connected thereto. Duringsuch major workover operations, situations-may even arise Furthermore,the positioning of wellhead where it is necessary to remove the entirewellhead assembly to the surface. However, in order to carry out some ofthe more simple production, workover and maintenance operations, such asthe perforation of well casings, the opening of a packer, the removal orinsertion of a valve, the cleaning of paraffin from a tubing string,etc., it has been found both convenient and necessary to develop anentirely new line of well tools adapted for through-theflowlineoperations. Preferably, in these operations, tools can be pumped througha well string" from some remote location, often hundreds of feet awayfrom the well. Upon entering the well with such tools, the tool ispositioned for carrying out the desired operation and then removed,generally by reverse circulation.

While the problems encountered in pumping a tool to the bottom of thewell tubing string, or to a single stop shoulder, are fairly readilysolved; the problems encountered in pumping a tool to a preselectedposition intermediate a series of similar positions is far moredifficult. This is especially true where it is necessary to position atool in a select one of a series of identical locations locatedlongitudinally along the well string. Such positioning, of necessity,requires an accurate locating or indexing system adapted forthrough-the-fiowline use in the curved fiowlines generally used tocommunicate with underwater installations.

In the past, well tools, such as gas lift valves and check valves, havebeen run into preselected positions in well strings through means ofwire line devices extended through the strings. Such devices weregenerally lowered into the well strings on a wire line and activated bysaid line at a selected point to force the tool carried by the line intoa selected pocket or mandrel. In this case, the length of the wire linerun into the string indicated the depth of the tool and, forces impartedthrough the wire line at the selected depths were utilized to activatean installation. mechanism secured to the wire line.

Wire line systems have proved effective when used in land based wellshaving relatively straight strings extending into the earth. In suchwells, tools secured to the wire line descend directly down the wellstring by virtue of their weight and the weight'of the wire line. Theenvironment surrounding oifshore wells is, however, critically differentfrom that of land based wells. In offshore wells wherein the wellheadassemblies are disposed on the bottom of the ocean, the line ofcommunication between the well and the cooperating surface or possiblyunderwater operating or workover station includes lengths of flowlineextending between the station and the wellhead assembly. Due to-therelatively large depths encountered in offshore drilling operations,ranging in hundreds of feet, it is impossible to maintain the fiowlinesextending between surface stations and the wellhead assemblies in astraight condition. For this reason, the

- fiowlines are flexible tosome extent, and generally include'curves ofvarying degrees. Because of these curves, the lowering of tools throughthe flowline and into the well string through means of land base typewire lines proves difficult, if not impossible. It is believed apparentthat the. reliance of tool weight to impart movement through a curvedflowline will result in hanging up of the tool in the curved andhorizontal sections of the fiowline and also in fouling of thewii'eline.

It is noted that curved fiowlines communicating with underwater wellstrings are not limited to lines extending to stations located on thesurface of the body of water above the wellhead. For example, it isanticipated that fiowlines may run along the bottom of the ocean to astation disposed thereon remote from the wellhead assembly, In thelatter case, however, the problems encountered'with the use of wire linelowering are still Q aresent, since such flowlines are likely to becurved and on along the relatively horizontal bottom of the ocean.

In addition to the aforediscussed wire line locating ystems, no-gosystems have been used to selectively ocate tools within pockets ormandrels disposed along vell strings. Such systems rely on the use ofmandrels raving different diameters and on the use of mating, eating orinstallation diameter carried by the tool deired to be located. Inactual application, the mandrels u pockets are located at spacedlocations along the eng'th of the string or conduit in which they areformed ind decrease in size from the top or upstream location 0, thebottom or downstream location. With this arttngement, a tool having aninstallation diameter secured hereto will pass through mandrels havingdiameters arger than the installation diameter and will seat in he firstmandrel encountered having a diameter smaller han that of theinstallation diameter. Movement beond the desired mandrel is preventedby abutment with he installation diameter with the mandrel diameter.thus, it can be seen that the no-go system provides a neans whereby atool may be positioned in one of a :eries of mandrels positioned in aconduit -or well string. Furthermore, since the system is not dependenton wire ine actuating means, pumpable carrier tools may be itilized topropel the tool and the desired installation liameter secured thereto tothe preselected position. lhus, such systems may be utilized in curvedand horizontal flowlines.

The use of no-go systems has the disadvantage, lowever, that the numberof positioning mandrels that nay be located in the well string isseverely limited due the reduced area required at each of said mandrels.This limitation results from the fact that the mandrels may only bereduced in diameter to a-size sufiicient to let tools pass therethroughto successive mandrels. In addition to the limitation in number, theno-go sys-- tem is also often limited in the type of mandrel that can beused therewith, since certain mandrels and tools cooperating therewithwill not accommodate the reduced diameters required by the system.

It is recognized that various systems have been developed in the pastwhich provide for indexing in conduits without the use of either theabove wire line or no-go systems; Typically, these devices includemagnetically, electro-magnetically and mechanically actuated tools. The,mechanisms used in such tools and the mandrels co operating therewithhave not, however, proved infallible. Furthermore, these mechanisms aregenerally expensive to fabricate and maintain.

Thus, the need for a tool carrier adapted to pass through curved tubingor fiowlines extending into underwater Well strings is still present.Furthermore, the necessity of the versatile and practical selectingmechanism to be used in combination with such carriers to selectpreselected pockets or mandrels within the well string is believedobvious. It was with these considerations in mind that the presentinvention was developed.

It is, therefore, an object of the present invention to provide a systemto pass well tools through a well string into preselected pockets ormandrels disposed in communication therewith.

Another object of the invention is to provide a flexible apparatusadapted to be pumped through curved and horizontal sections of;flowlines communicating with a well string. In this respect, it is amore specific object of the invention to provide flexible coupling meansto secure such an apparatus together for movement through curvedsections of a flowline.

A further object of the invention is to provide an apparaus to passthrough a well string and automatically install a tool secured theretoin one preselected mandrel of a plurality of substantially identicalmandrels spaced along the well string. In. this respect, it is anotherobject of the invention to provide an installation mechauism adapted tobe selectively operated by said apparation therein. In relation to thisobject, it is another object to provide said carrier with means toselectively release and remove the tool from the preselected position.

Broadly, the present invention provides a system for installing a toolin a preselected tool receiving position within a conduit having aseries of such tool receiving positions formed therein at longitudinallyspaced locations. The system includes identical indexing areas locatedwithin the conduit at each of said positions. The latter areas areidentical to each other in internal diameter, but have a diameterdifferent from internal diameter of the conduit. The system furtherincludes a carrier operatively engaging the tool to propel it throughthe conduit and a selectively operable installation mechanism secured tothe tool and adapted to be activated to install it in the preselectedposition. An indexing device is operatively secured to the installationmechanism and carries a sensing means cooperable with the indexing areaswithin the conduit to sense the number of such areas through which theindexing device has passed. The indexing device also carries an actuatorcooperable with the sensing means to activate the installation mechanism and thus install the tool in the desired preselected tool receivingposition.

More specifically, the installation mechanism of the above describedsystem comprises a housing member adapted to be secured to the tool andpropelled therewith through the conduit and at least one dog carried bysaid housing and being adapted to be extended therefrom into lockedengagement with the conduit. Biasing means are interposed between thedog and the housing to provide dot extension of the dog and retainingmeans carried by the housing to normally hold the dog in retractedposition. The retaining means is operable to selectively activate thebiasing means to extend the dog into engagement with the conduit.

The invention further includes a coupling for flexibly connecting a pairof elements, such as the aforementioned tool and the installationmechanism, together for movement through a curved conduit. The couplingcomprises a first flange fixed to and spaced from one of said elementsand a second corresponding flange'fixed to and spaced from the other ofsaid elements. To complete the coupling, a sleeve extends over theflanges and has a mid-portion received loosely therearound. The ends ofthe sleeve have internal shoulders formed therein of a reduced diameterless than that of the flanges received therein. These shoulders arepositioned between the flanges in the elements fixed thereto and arespaced apart sufficiently to allow the respective flanges to movetowards and away from each other within the mid'portion of the sleeve.Through the latter arrangement, the elements fixed to the flanges maymove relative to'each other when they pass through curved sections of aconduit. However, the shoulders positioned between the flanges and theelements fixed thereto prevent said elements from being completelyseparated from each other.

The invention, and the enumerated and other objects,

will be more fully understood when viewed in light of the followingdetailed description and the accompanying illustrations, wherein:

FIGURE, 1 is a schematic view diagrammatically illustrating anunderwater wellhead assembly having a tubing string extending downwardlytherefrom;

FIGURES 2A, 2B and 2C are partial sectional views of; thethrough-the-flowline. insertion assembly of the. in-

vention;

FIGURE 3 is an exploded view of the indexing device,

illustrated in FIGURE 2B, with certain retaining elements omittedtherefrom for the sake of clarity;

FIGURE 4 is a perspective view of the actuating rod of the FIGURE 3device;

FIGURES 5 and 6 are longitudinal sectional views of the startingindexing nipple and the locking indexing nipple, respectively, adaptedto be' assembled in a tubing string as indexing areas;

FIGURE '7 is a perspective view of the actuating probe to be used in theinstallation or lockdown mechanism of the assembly shown in FIGURE 2C;

FIGURE 8 is an exploded perspective view of the double knuckle jointillustrated in the assembly of FIG- URE 2C; and,

FIGURES 9A and 9B are longitudinal views of a running assembly adaptedto retrieve tools that have been positioned with the assembly of FIGURES2A, 2B and 2C.

Referring nowto FIGURE 1, a wellhead assembly 10 is shown positionedbelow the surface of a body of water 11 on the floor 12 thereof. Thewellhead assembly comprises a platform 13 secured to the top of aconductor pipeior surface'casing 14, which in turn extends into theearth below the body of water 11 and is preferably eemented in position.The wellhead assembly 10 is shown as being provided with two or morevertically positioned guide columns 15 and 16 which are fixedly securedat their lower ends through the platform 13. A well casinghead 17 ismounted on the top of the conductor pipe 14 and has a control equipmenthousing 20 secured thereto. The equipment housing 20 closesthe top ofthe casinghead and/ or any casing and tubing suspension equipmentemployed on the wellhead assembly, as well as various control valves inother control equipment used on the well.

A pair. of fiowlines 21 and 22 emerge from the'housing in gentlysweeping'curves from a vertical position. These lines extend upwardly toan operating station 23 located at the surface of the body of water 11at a location approximately above the assembly 10. In addition to thesurface casing 14, a well or tubing string 24 extends down from thecasinghead 17 in suspended relationship therewith. The string 24 isprovided with a starting nipple 25 at the upper end thereof and aplurality of indexing and locking nipples 26 spaced longitudinallytherealong below the starting nipple. Although only two locking nipples26 are illustrated, it is to be understood this number may be increasedwithout departing from the invention. The detailed structure andoperation of the starting nipple 25 and the locking nipples 26 will bedeveloped subsequently with respect to FIGURES 5 and 6. The string 24further includes a circulating nipple 27 located therein below thelowermost nipple 26 and a packer 30 positioned below the nipple 27 insealing engagementwith the easing 14. In order to isolate the interiorof the casing 14 from the formation into which it extends, a drillablebridge plug 31 is positioned therein below the lowermost end of thetubing string 24.

In the illustration of FIGURE 1, the fiowlines 21 and 22 are incommunication with the tubing string 24 and the annular space betweensaid string and the casing, respectively. It is to be understood,however, that in installations wherein double tubing strings areutilized, both fiowlines would be in communication with a tubing string.Thus, with either a single or a double tubing string, circulation may beaccomplished through means of the flowlines 21 and 22. At this point itis noted that the flowline 21 communicating with the tubing stringhaving the nipples therein emerges from the equipment housing 20 in agently sweeping curve, preferably having a radius of five feet or more.The use of such a radius insures that tools may be passed through theline without the danger of I fouling or hanging up.

The operating station 23 illustrated in FIGURE 1 is typical of thoseused in offshore drilling and production operations and includes aderrick 32 extending upwardly therefrom and a traveling block 33 carriedby the derrick. A well or opening 34 extends through the operatingstation directly below-the derrick 32 and is open to the body of waterin which the station floats. It is through this well that the fiowlines21 and 22 extend from the station into the body of water 11. Preferably,the fiowlines 21 and 22 are secured to the station through winches 35and 36, respectively. In order to maintain the station 23 at a locationapproximately above the wellhead assembly 10, anchor lines 37 and 40extend downwardly therefrom to heavy anchors (not shown) positioned onthe floor 12.

Referring now to FIGURES 2A, 2B and 2C, therein is illustrated a partialvertical section of the assembly adapted to run tools from the station23 through the flow line 21 into selected nipples 26 in the tubingstring 24. The assembly includes a pair of spaced motor swabs 41 and 42joined together through a universal type ball joint 43. The motor swabs41 and 42 are of relatively conventional structure and include resilientcups 44 and 45, respectively, adapted to sealingly engage the walls ofthe conduit through which the swabs are run. T-hus, fluid pressureimposed'within such a conduit will function to force the motor swabs andany elements secured thereto through a conduit towards the direction oflowest pressure. A fishinghead 46 is secured to the upper motor swab 41in order to facilitate removal of the swabs and any elements securedthereto in case the swabs and/or elements should become fouled within aconduit.

The motor swab 42 is joined to an indexing mechanism 47 through a doubleball joint assembly 50. The sole purpose of the indexing mechanism, aswill be developed subsequently, is to selectively operate aninstallation mechanism 51 secured to the indexing mechanism through adouble ball joint connection 52. The double ball joint connection 52 hasa flexible cable 53 extending therethrough and into the installationmechanism 51. This cable, as will be developed in detail subsequently,has one end secured to the actuating rod 54 of the indexing mechanismand the other end secured to a retaining probe 55 in the mechanism 51through means of a stop 58. As is illustrated in detail in FIGURE 2C,the retaining probe 55 normally assumes a position entirely Within thehousing 56 of the mechanism 51. In this position, the probe functions topartially inactivate the installation mechanism, as will be-developed indetail substantially.

The lower end of the mechanism 51 is flexibly secured to the well tool57, desired to be positioned by the installation assembly, through meansof a double acting knuckle joint 60. Although the tool 57 illustratedtakes the form of a storm choke, it is to be understood that theassembly is not limited to use in positioning anyone particular tool.The storm choke illustrated is of conventional internal character anddiffers from commercially available units only in that it utilizes acompact packing arrangement in order to minimize its length. Thispacking arrangement comprises resilient packing elements 61 fixed to thetool 57 and adapted to sealingly engage a mandrel in which the tool maybe received.

Referring now to the detailed structure of the indexing mechanism 47,illustrated in vertical section in FIG- URE 2B and in perspective inFIGURES 3 and 4. The mechanism comprises a housing section 62 fabricatedof several joined tubular sections and having housed therein theelements of the mechanism, including the previously mentioned actuatingrod 54. The rod 54, as illustrated in full in FIGURE 4, is a unitarystructure and extends through substantially the entire length of thehousing section 62. At this point, it is noted that the rod 54 is ofstepped configuration and includes a portion of enlarged actuatingdiameter 63 and a grooved portion of reduced diameter 64 adapted tocooperate with the internal structure of the indexing mechanism, as willbe developed subseuently. The remaining portions of the rod 54 are ofsub- :antially equivalent diameters, including the upper and )wer endsthereof fixedly secured to a cap member 65 and retention collar 66,respectively, as by screw threads. As

hown in FIGURE 28, the rod 54 is slidably received in he housing section62 and is resiliently urged upwardly herein by a compression coil spring67 interposed beween the cap member 65 and the housing section. In thelustrated position, upward movement of the rod is retrained by fourretention dogs 70 pivotally secured to the rousing section 62 at pivots71 and having housed ends 2 urged into locked engagement with theretention colar 66 by compression coil springs 73. It is noted that heexterior sides of the dogs 70 include rollers or fol- Jwers 74 extendinglaterally of the housing section 62. ."hrough these rollers, the dogs 70are pivoted about the rivots 71 when the mechanism passes through anarea in he fiowline of sufficiently reduced diameter, thus releasng theretention collar 66 and permitting the rod 54 to move under action ofthe spring 67. It is noted that the logs 70 are designed so that theymust all be released imultaneously in order to release the retentioncollar 66. Thus, the collar can only be released upon simultaneous\assing of all of the rollers 74 through an area of reduced liameter.

Upward movement of the rod 54 is normally limited by l latching arm 75having an arcuate end 76 received in he grooved portion 64. The latchingarm 75, as will be leveloped in detail subsequently, is resilientlyurged into :ngagement with the rod 54 and is adapted to be selecivelyswung out of this engaged position to release the d. When the latchingarm 75 is engaged in the grooved aortion 64 and the dogs 70 arereleased, the rod 54 moves lpwardly by a distance approximately equal tothe length )f the grooved portion 64. Abutment of the arcuate end 76with the lower shoulder of the grooved portion 64 thus est-riots upwardmovement of the rod. When the rod 54 s at the upper extremity ofmovement, as limited by the grooved portion 64, the cap 65 is forcedinto a position where it holds for restoring dogs '77 in a substantiallyhorizontal position. In this position, the rearward ends of .he dogsextend laterally from the housing section-62 to 1 slight extent. At thesame time, the inner ends of the logs are continuously biased downwardlyby leaf springs 30 interposed between the housing section and the uppersides of the dogs. It is noted that the springs 80 merely function tobias the dogs 77 inwardly about the pivots 81 on which they are mountedand that this biasing force is insuflicient to compress the spring 67.With the dogs 77 in the substantially horizontal position, movement ofthe :logs through an area of reduced diameter will function to pivot thedogs inwardly, thus forcing the inner ends of the dogs against the cap65. As dogs are forced against the cap 65, the shaft 54 is forceddownwardly to a position wherein the dogs 70 may re-enga-ge theretention collar 66, thus restoring the shaft to its initial position.At this point it is noted that the laterally exended ends of the dogs 77and the extended rollers 74 of the dogs 70 are designed so as to becompressed by like areas of reduced diameter. Thus, a reduced diameterwhich functions to compress the rollers 74 will also function to pivotthe dogs 77 about the pivots 81. Through this arrangement, the shaft 54moves both upwardly and downwardly within the housing section 62 whenthe section passes through an area of sufficiently reduced diameter.This arrangement, as will be developed subsequently, functions toactivate sensing or counting means within the indexing mechanism.

The internal structure of the indexing mechanism will now be describedwith reference to FIGURES 213 and 3. This structure includes fixed orstationary elements comprising a latching arm bearing plate 82, alatching arm spacer plate 83, a latching arm backing plate 84, a spacer.

plate 85, and a ratchet backup plate 86. The plates 82 to illustrated inFIGURE 3.

within the rectangular-shaped peripheral slots illustrated in FIGURE 3.In addition to securing the plates together, the spacer bars 87 securethe assembled plates within the housing section 62. The latter functionis accomplished by securing the lowermost ends of the spacer plates inrecessed slots 90 formed in the external surface of an externallythreaded nipple 91 threadably engaging the housing section 62. Itisnoted that the nipple 91 is formed as a unitary member having threadson both ends thereof, with the upper of said ends acting as a receiverfor the housing section 62 and the lower of said ends acting as areceiver for the section of the indexing mechanism carrying theretention dogs 70. Although only two of the spacer bars -87 areillustrated in FIGURE 25, it is to be understood that the 'mechanismincludes four of such bars, each of which is received in one of therectangularshaped peripheral recesses formed in the plates 82 to 86 Thelatching arm 75, referred to previously, is pivotally secured betweenthe plates 82 and 84 by a dowel 92 extending through said plates. Thearm 75 is urged in a clockwise direction through means of a pin 93 fixedthereto and extending slidably through a slot 94 in the end plate 82,which pin is resilientlycontacted by a leaf spring 95 carried by thedowel 92. A second releasing or disengaging pin 96 is fixed to the upperside of the arm 75 and extends slidably through a slot 97 in thelatching arm backing plate 84. The latter pin, as will be developed indetail subsequently, is disposed so as to be selectively contacted tourge the arm 75 in a counterclockwise direction, thus removing it fromthe limiting diameter in the actuating rod 54. v

counterclockwise movement is selectively imparted to the pin 96 and theattached latching arm 75 through an index plate 100 mounted forconcentric movement about the rod 54. A finger 101 is fixed to the plate100' and positioned so as to move in a path wherein it will abut againstthe pin 96 upon rotation of the plate 100. Thus, I

upon clockwise movement of the plate 130, the finger 161 will abutagainst the pin 96 and pivot the latching arm 75 out of engagement withthe limiting diameter 64 of the actuating rod. The plate 100 is mountedfor pivotal movement with respect to the plate 85 through means of adrum 102 extending slidably through the plate 85 for rotational movementwith respect thereto. Through means of a shoulder.103 formed thereon anddimensioned to slidably engage the plate 85, the drum 102 also functionsto position the index plate 100 between the plates 84 and 85. The drum102 and the indexing plate .100 secured thereto are resiliently urged ina clockwise direction by a coil spring 104 having one end received in anopening 105 in the drum and the other end received in an opening 1&6 inthe fixed spacer plate 85. V

Rotational movement imparted to the drum 102 through the spring 104 iscontrolled through means of a ratchet drum 107 received on the upper endof the drum 102 for concentric movement with respect thereto in onedirection. Movement of the'drum 107 with respect to the drum 102 islimited to one direction through means of resiliently biased pawls 110,11.1 and 112 mounted on the lower surface of the drum 107 for engagementwith ratchet teeth 113 formed on the outer surface of the drum 102. Thepawls 110 to 112 are of relatively conventional nature and comprise atooth section secured to a resilient leaf section. The pawls are mountedso that the leaf sections thereof are backed up, thus resiliently urgingthe tooth sections into contact with the cooperating ratchet teeth 113.It is noted, that in the assembled position, the teeth on the pawls 110to 112 assume an aligned relationship with the ratchet teeth 113.Through the ratchet and paw] arrangement on the drums 102 and 107, thespring 104 functions to turn the drums 102 and 107 clockwise as a unit.However, through the ratchet ar rangement, the drum 102 may always bemanually turned counterclockwise with respect to the drum 107.

Referring now to the control means adapted to selectively limit theclockwise rotation that may be imparted to the drums 102 and 107 throughthe spring 104 it will be noted that this means comprises a ratchet cage114 mounted on the ratchet backup plate 86 for slidable movement withrespect thereto through means of guide bolts or dowels 115 extendingslidably through the cage 114 into threaded engagement with plate 86.The cage 114 is resiliently urged away from the plate 86 by acompression coil spring 115 interposed therebetween in concentricrelationship with respect to the rod 54. The enlarged portion 63 on therod 54 is dimensioned so as to abut against the cage 114 on downwardmovement of the rod with respect to the cage. However, the diameter ofthe rod below the enlarged portion 53 is sufficiently reduced to freelyslide through the cage 114. Thus, downward movement of the rod 54 forcesthe cage towards the plate 86 and upward movement of the rod permits thespring 116 to force the cage away from the plate 86. The cage 114further includes short ratchet fingers 117 and 120 and long ratchetfingers 121 and 122 fixedly secured thereto and extending slidablythrough peripheral slots in the plate 86. These fingers are positionedso as to selectively engage the ratchet teeth 123 on the drum 107, aswill be developed in the subsequent description of the ratchetoperation.

In operation, the spring loaded ratchet cage 114 moves up or down on theguide =bolts 115 during travel of the enlarged portion 63 of the rod 54.When the cage is moved downward, the ratchet teeth 123 are engaged bythe long fingers 121 and 122 "at the outset, but are released by thesefingers when slots 124 and 125- formed in the respective long fingersassume an aligned relationship with the ratchet teeth i123. At thispoint, the ratchet teeth 123 are released and the drums 107 and 102 moveclockwise through 15", at which point the ratchet teeth 123 engage theends of the short fingers 117 and 120. When the enlarged portion 63moves upwardly, the spring 116 forces the cage 114 up, thus withdrawingthe short fingers 1'17 and 120 from the ratchet 123 in freeing the drum107 for clockwise movement through 15, at which point the long fingers121 and 122 re-engage the ratchet 123. Hence, the drums 107 and 102 move30 clockwise each time the rod 54 moves up and down, as when thepreviously described dogs 70 and 77 encounter an area of reduceddiameter. It is noted, that although the described ratchet arrangementlimits the indexing mechanism to 12 counts (i.e., twelve up and downmovements of the rod 54-), the ratchet arrangement could be modified,within the scope of the invention, to vary the number of such countswhich the mechanism is capable of handling.

From the above description, it can be seen that as the ratchet drum 107moves, so does the finger 101 on the index plate 100. The position ofthe drum 107 with respect to the index plate 100 can be adjusted byrotating the drum 102 with respect to the drum 107. Through thisadjustment, the number of counts (i.e., up and down movements of the rod54) required to turn the indexing plate 100 to a position where itwillrelease the latching arm 75 can be adjusted. The number of countsinstalled by rotating the drum 102 with respect to the drum 107 can besensed by listening to the click of the pawls 110 to 1:12 on the ratchetteeth 113 and can be substantiated through means of indexing markings126 on the indexing plate and an indexing pointer 127 on the plate 85.Thus, in operation, after the installed counts have been expended, thefinger 101 engages the releasing pin 96 on the latching arm 75.Preferably, the counting arrangement is designed so that the latchingarm is moved by the finger 101 when the rod moves downwardly. Thisreduces the force required to move the arm 75 to the small value of thespring force imparted by the spring 95, because the spring load on therod 54 is carried by the aforedescribed restoring dogs 77. With thelatching arm out of its restrictive position in the grooved portion 64,the rod 54 is free to travel to the upper extremity of the indexing toolthe next time the retention dogs 70 are released. When this rod movementoccurs, the cable 53 is pulled upwardly along with the probe 55, and thecap 65 rotates the restoring dogs '77 to a position where theiractivating surfaces are below the outside diameter of the housingsection 62. The pulling of the probe 55, in turn, functions to activatethe installation mechanism 51 and thus position the tool 57, as will bedeveloped in detail subsequently.

Referring now to the internal structure of the installation mechanism 51illustrated in FIGURE 2C, this structure comprises a tubular housing 55having a probe 55 slidably received therein, as described previously.The upper end of the housing 56 has four slots 130 extendingtherethrough at intervals around its circumference spaced apart by Slots131, corresponding in configuration to the four slots 130, extendthrough the lower end of the housing 56 at 90 intervals offset from theintervals of the slots by 45". As is clearly illustrated in the lefthandsection of the upper slot 130, each of the slots 130 carries a dog 132mounted therein for pivotal movement about a shaft 133 extending throughthe housing 56 transversely of the slot 130. The dogs 132 areresiliently biased outwardly with respect to the housing. 56 by acompression coil spring 134' interposed between one end of the dog and aweb 135 formed in the housing 56 at the upper inner end of the slot.130. The degree to which the upper end of the dog 132 can be extendedwith respect to the housing 56 is limited by a stop web 136 formed inthe housing 56 at the lower end of the slot 130 in a position wherein itwill abut with the lower end of the dog upon extension of the upper endthereof. Dogs 137, corresponding identically to the dogs 132, arereceived in each of the lower slots 131 for pivotal movement withrespect to the housing 51 in a manner identical to that above-describedwith respect to the dogs 132. It is noted that the slots 131 and dogs137 are inverted with respect to the slots 130 and dogs 132 so that thedogs 137 extend from the lower ends of the slots, rather then the upperend of the slots as do the dogs 132.

The operation of the installation mechanism 51 will now be describedwith reference to the structure thereof illustrated in FIGURE 2C and theperspective view of the probe 55 illustrated in FIGURE 7. The probe 55is of fluted cross-sectional configuration and includes fourperipherally spaced longitudinally extending protrusions 140 spacedtherearound at 90 intervals and separated by recessed flutes 141. Theprotrusions 140 extend over only the mid-portion of the probe :body andhave spaced therebelow a pair of inclined stop protrusions 142 locatedat dimetrically opposed positions in alignment wit-h a diametricallyopposed pair of the flutes 141. Through the particular flutedconfiguration of the probe 55, it is adapted to be seated in the housing56 and selectively unseated, through means of the cable 53, to operatethe installation mechanism 51.

Initially, when the mechanism 51 is prepared for insertion into aconduit in which it is to be positioned, the probe 55 is forced into thehousing 55 to a position where the protrusions 142 seat on a shoulder143 formed in the lower end of the housing. As the probe 55 is insertedinto the housing 56, it is manually turned to a position where theflutes 141 are aligned with the inner ends of the dogs 132 and, as aresult, the protrusions 140 are aligned with the dogs 137. With theprobe and housing so orientated, forcing the probe into seatedengagement with the shoulder 143 functions to retract the dogs 137 intoa flush position with respect to the outer surface of the housing 56,while the dogs 132 remain undisturbed in their extended position.Retraction of the dogs 137 by the probe 55 is facilitated by theinclined shoulders 1 1 144 formed on the lower ends of each oftheprotrusions 140.

With the probe received in the housing 56, the mechanism 51 is incondition to pass downwardly through a conduit without interruption.During such movement, the dogs 132 are free to contract uponencountering any areas of reduced diameter and the dogs 137 areretracted in a position where they will not hang up onsuch reduceddiameters. Upon reaching the desired position in the conduit, however,the indexing mechanism 47 pulls the probe 55 to a position where boththe upper dogs 132 and the lower dogs 133 assume an extended positionwith respect to the housing 56. At this point, the extended dogs 137will abut against the next area of reduced diameter encountered in theconduit through which the mechanism 51 is passing and, as a re sult theassembly of components illustrated in FIG- URES 2A, 2B and 2C will bestopped within the conduit. Furthermore, if this stopped position isalso provided with means to engage the dogs 132, the mechanism 51 willbe locked within the conduit against move ment in either direction.

FIGURE 8 illustrates an exploded perspective view of the double actingknuckle joint illustrated in partial section in FIGURE 2C. This joint isdesigned to facilitate ready separation of the elements joined therebywhile also providing a strong and flexible connection between theseelements when they are joined. Although the joint is shown coupling themechanism 51 and the well tool 57, it is to be understood that the jointis equally well adapted for use in flexibly joining other and varyingelements. For example, it is anticipated that a joint constructed as thejoint 60 could be used in place of the double ball joint connection 52illustrated in FIGURE 2B.

As illustrated, the joint 60 includes a first annular flange fixed toand spaced from the housing 56 through means of a tubular section 146.The joint also includes a second annular flange 147, corresponding tothe flange 145, fixed to and spaced from the tool 57 by a tubularsection 150. The flanges 145 and 147 are dimensioned so as to be looselyreceived within a pair of arcuateshaped cylindrical sections 151 and152. The latter sections are adapted to be assembled in juxtaposedrelationship to form a closed cylinder around the flanges 145 and 147.Alignment of the sections 151 and 152 in the juxtaposed relationship isfacilitated through means of dowels 153 fixed to and extending from thesection 152 and mating openings 154 formed in the section 151. At-

ter the sections 151 and 152 are assembled in the juxtaposedrelationship, they may be secured through means of a sleeve 155 adaptedto be threaded over their outer surfaces, as illustrated clearly inFIGURE 2C. In order to limit the extent to which the flanges 145 and 147may move longitudinally within the assembled sections 151 and 152, eachof these sections are formed with internal shoulders at the endsthereof. These shoulders, designated as 156 and 157 in the section 151and as 160 and 161 in the section 152, have a diameter less than theflanges 145 and 147, but greater than the sections 146 and 150. Inaddition, the shoulders are spaced apart sufficiently to allow theflanges 145 and 147 to move towards and away from each other when thesections 151 and 152 are assembled therearound.

From the foregoing description, it can be seen that the double joint 60provides means whereby a pair of elements may be flexibly connected andreadily disengaged. Furthermore, the joined elements are arranged fordouble knuckling, thus maximizing the flexibility ofthe elements joinedthereby. The latter feature is of particular importance, since it isoften the critical factor limiting the radius of curves in a conduitthrough which joined elements may be passed.

Referring now to FIGURE 5, therein is illustrated a vertical section ofthe starting nipple 25 illustrated dia- 12 grammatically in FIGURE 1.The nipple includes an internally stepped upper section 162 and anexternally stepped lower section 163 dimensioned to be secured to aconduit, such as the tubing string 24, into which the nipple isassembled. Sections 164 and 165 are formed in the upper and lowerportions, respectively, of the nipple and are equal in size to theinternal diameter of the conduit into which the nipple is assembled.Intermediate of the sections 164 and 165 the internal surface of thenipple converges through smoothly tapered sections 166 and 167 to areduced diameter counting area 170. The counting area 170 is of adiameter sufliciently small to actuate both the dogs 76 and 77 carriedby the indexing mechanism 47. Thus, upon pumping of the assemblyillustrated in FIGURES 2A, 2B and 20 through the nipple 25 located inthe tubing string 24, the indexing mechanism, as described previously,advances by one count. At this point, should the indexing mechanism havehad only one count installed thereon initially, the

probe 55 will be pulled from the installation mechanism 51 and themechanism will be in condition to lock in the next encountered lockingnipple 26. However, if the indexing mechanism 47 had more than one countinstalled therein, the probe 55 will not be pulled after the assemblypasses through the nipple 25, but rather will be pulled at somesubsequent location in the tubing string Where the indexing mechanismhas counted a nnmberof counts equal to the counts initially installedtherein.

FIGURE 6 illustrates a vertical section of one of the locking nipples 26shown assembled into the tubing string 24 in FIGURE 1. It is noted thateach of the nipples 26 used in a system, such as illustrated in FIGURE1, is identical to the other. The nipple 26 includes internally steppedand externally stepped sections 171 and 172, respectively, at its upperand lower ends dimensioned to be secured to a conduit into which thenipple is assembled. The nipple further includes enddiameter sections173 and 174 and an intermediate diameter section 175 having dimensionsequal to the internal diameter of the conduit into which the nipple isassembled. A recessed locking bore 176 is positioned between thesections 173 and 175 and has a length equal to or slightly greater thanthe longitudinal distance between the end surfaces of the dogs 132 and137 carried by the housing 55 of the installation mechanism 51. Throughthe inter-relationship between the dimensions of the installationmechanism 51 and the locking bore 176, the dogs 132 and 137 of theinstallation mechanism will function to lock the mechanism Within thelocking bore when the mechanism enters the bore with the probe 55 pulledto a point where it releases the dogs 137. It is noted, however, thatwith only the dogs 132 extended, the installation mechanism 51 will befree'to pass through the locking bore in a downward direction, since thedogs 132 will be compressed by any obstructions encountered during suchmovement.

A pack-oif and counting area 177, having a diameter equal to thediameter of the counting area 170 of the nipple 25, is located Withinthe nipple 26 between the sections 174 and 175. The area 177 leadssmoothly into the sections 174 and 175 through tapered sections 180 and181. The pack-off and counting area 177 is located in a positionrelative to the locking bore 176 wherein it will sealingly pack-01f thepacking elements 61 of the tool 57 when the installation mechanism 51 islocked within the locking bore 176. In addition to performing thepack-01f function, the counting area 177 will also function to activatean indexing mechanism passing therethrough in a manner corresponding tothat described with reference to the counting area 170 of the nipple 24.

Thus, the nipple 26 functions as a counting area for the indexingmechanism 47, a locking recess for the installation mechanism 51 and apack-off diameter for the packing elements 61 secured to the tool 57.The latter two functions occur only if the counts installed on the indexing mechanism have been expended prior to the time the installationmechanism enters the nipple. If the counts have not been so expended,the assembly shown in FIGURES 2A, 2B and 2C will pass completely throughthe nipple 26, removing a count from the indexing mechanism 47 when itpasses through the area 177. Thus, it can be seen that one count isexpended from the indexing mechanism 47 as it passes through the nipple25 and each of the subsequent nipples 26. After all the counts have beenexpended, the indexing mechanism functions to pull the probe 55. thusexpanding all of the dogs on the installation mechanism 51 and reparingthe installation mechanism for locking engagement with the next nipple26 encountered. It can thus be seen that one count installed on theindexing mechanism will function to lock the installation mechanism 51in the first nipple 26 encountered. Likewise, a greater number of countson the indexing mechanism 47 will function to lock the installationmechanism 51 in the nipple 26 having a number equal to the number ofsaid counts, when said nipples are numbered successively, beginning withthe first nipple be .low the starting nipple 25.

After the installation mechanism 51 and the tool 57 have been locked ina preselected nipple 26, the insertion assembly, comprising the motorswabs 41 and 42, the double ball joint 50, the indexing mechanism 47 andthe double ball joint connection 52 may be removed from the tubingstring 24 by reverse circulation. This removal is facilitated by abreak-away mechanism 182 pivotally secured to the lower end of thedouble ball joint connection 52 and releasably engaged in the upper endof the installation mechanism 51. An external view of a breakawaymechanism 182A, corresponding identically to the mechanism 182, is shownin full lines in FIGURE 9B. The detailed function of the mechanism 182Awill be developed subsequently with respect to the description ofFIGURES 9A and 9B.

The break-away mechanism 182 includes a unitary housing section 183pivotally received on the lower ball of the connection 52 and adapted topass into a cylindrical recess 134 in the upper end of the installationmechanism 51. The section 183 is slidably received in the recess 184 andis adapted to be retained within said recess through means of aretention arrangement adapted to expand into engagement with an annulargroove 185 formed within the recess 184. The details of the retentionarrangement will become apparent from the f0llO- ing description, whenviewed in light of the structures illustrated in FIGURES 2B and 9B.

The retention structure includes a V-shaped groove 186 formed in thesection 183 and having a split expansion ring 187 received looselytherein. The retention arrangement further includes a cylindricalsurface 190 of reduced diameter formed in the section 183 at a locationspaced slightly below the groove 186. A sleeve 191 is slidably receivedon the surface 190 and is normally retained in position thereon by aplurality of shear screws 192 threaded through the sleeve intoengagement with the openings in the section 183. To conclude theretention arrangement, a second split expansion ring 193 is looselyreceived in a groove 194 formed in the section 183 directly below thesurface 1%. In order to secure various elements to the section 133, andto prevent the shear screws 192 from passing into the opening extendingthrough the section, the lower end of the section is threaded to receivea mating threaded element, such as a sleeve 195 as illustrated in FIGURE2B or a probe 196 as illustrated in FIGURE 9B.

In operation, the break-away mechanism is initially assembled asillustrated by the mechanism 182A in FIGURE 9B. When so assembled, themechanism is in condition to be forced into the cylindrical ecess 184,thus slightly compressing the expansion rings 187 and 193, asillustrated in FIGURE 23. Upon entering the groove 185, the expansionring 186 expands slightly and removal of the break-away mechanism fromthe recess 18 i is prevented by abutment of the expansion" ring with theupper shoulder of the groove 185 and the upper edge of the sleeve 191.Thus, once the mechanism 182 is forced into the recess 184, separationof these elements is prevented. However, upon imposing sutlicienttensile force on the mechanism 132 with respect to the installationmechanism 51, the expansion ring 187 will be forced the sleeve 1'91 toan extent sufficient to shear off the screws 192. At this point, theexpansion ring 187 will ride out of ti e groove res and fall onto thecylindrical surface 1%. The latter surface is of sufiiciently smalldiameter to permit the walls of the recess 134 to compress the expansionring to a point Where it may be pulled through the groove 184, thuspermitting the mechanism 182 to be removed from engagement with theinstallation mechanism 51. As the mechanism 182 is so removed, theexpansion ring 193 will expand to a diameter where it abuts against thelower end of the sleeve 191, thus retaining this sleeve on the section183 for removal therewith.

Referring now to FIGURES 9A and 9B, therein is illustrated a runningassembly adapted to be pumped through a conduit to retrieve aninstallation mechanism and tool positioned therein through means of theassembly illustrated in FIGURES 2A, 2B and 2C. The running assembly ofFIGURES 9A and 9B is identical to the running assembly illustrated inFIGURE 2A in that it includes pivotally joined motor swabs 2.39 and 201corresponding to the swabs 41 and 42, respectively, and a double balljoint assembly 292 corresponding to the assembly 59 secured to the lowerend of the swab 201. The lower end of the ball joint assembly 2tl2 ispivotally secured to the break-away mechanism 182A in a mannercorresponding to that illustrated between the ball joint connection 52and the housing section 183 shown in FIGURE 28.

In application of the assembly 197 in retrieving an installed toolwithin a nipple 26, the assembly would be pumped to the nipple throughmeans of conduits and fiowlines communicating therewith, such as theflowline 21 and tithing string 24 illustrated in FIGURE 1. It is notedthat at the time the assembly 197 is pumped to the nipple, the runningassembly used to initially install the tool in the nipple 26 has beenbroken away at the breakaway mechanism 182 and removed from the system.As the assembly 197 is pumped through the tubing string 24, it passesthe nipple 25 and the nipples 26 until it reaches the nipple 26 havingthe installation mechanism 51 engaged therein. At this point, the probe196 of the assembly is forced into the cylindrical opening extendinginto the mechanism 51, thus pivoting the dogs 13?. to a position wheretheir outer surfaces are flush with the outer surface of the housing 56.The latter function is accomplished since the probe 196 has a diametersubstantially equal to the diameter defined by the outside surfaces ofthe protrusions 140 on the probe 55 (i.e., a diameter only slightly lessthan the internal diameter of the opening extending through the housing56). The probe 196 is also dimensioned so as to permit the breakawaymechanism 182A to engage the recess 184 in a manner corresponding tothat described with reference to the break-away mechanism 182. Thus,when the assembly 197 is pumped into engagement with the mechanism 51,the assembly is locked to the mechanism while it retracts the upper dogs132. At this point, further downward movement of the assembly isrestrained by the dogs 137 and a pressure buildup will be sensed in thetubing string 24 and the fiowline 21 communicating therewith. Uponsensing such a pressure build-up, flow Within the tubing string andfiowline should be reversed to thus pump the assembly 197 and themechanism 51 and tool 57 secured thereto to the operating station 23.

To summarize, the system of the present invention provides means wherebytools may be installed and retriever rorn preselected locations in aconduit, such as a tubing tring. The apparatus of this system is adaptedto pass hrough curved fiowlines into well strings disposed at in-:xcessible and remote locations. Although the system has aeen describedwith reference to the installation of a term choke, it is to beunderstood that the invention may :qually Well be used for inserting andretrieving other vools.

The foregoing description of the invention is, therefore, nerelyintended to be explanatory thereof. Various :hanges in the details ofthe described system may be nade, Within the scope of the appendedclaims, without leparting from the spirit of the invention;

, I claim as my invention:

1. A system for installing a tool in a preselected tool receivingpositions formed therein at longitudinally ipaced locations, comprising:

(a) identical short indexing areas located Within the conduit adjacentsaid positions, said areas having an internal diameter less than theinternal diameter of the conduit;

(b) a carrier operatively engaging the tool and adapted to propel saidtool through the conduit;

(c) a selectively operable installation mechanism secured to the tooland adapted to be activated to install said tool in said preselectedposition;

(d) an indexing device operatively secured to said installationmechanism;

(e) sensing means carried by said indexing device and cooperable withsaid indexing areas to sense the number of said areas through which thedevice has passed; and,

(f) actuating means carried by said indexing device and cooperating withsaid sensing means to activate said installation mechanism to installthe tool in said preselected tool receiving position 2. A selectivelyoperable installation mechanism for securing a tool within a conduit,comprising:

(a) a housing member having a central bore and adapted to be operablysecured to the tool and propelled therewith through the conduit;

(b) at least one dog carried by said housing and being adapted to beextended therefrom into locked engagement with the conduit;

(c) biasing means to extend said dog from the heirsing; and V V (d) aprobe recipro-cably mounted with said bore,

(e) at least one shoulder formed on said pro-b eto engage and hold saiddog in retracted position,

(i) actuating means operatively connected to said probe to selectivelyreciprocate said probe, to release said dog; whereby said biasing meansextend said dog into locked engagement with said conduit.

3. An installation mechanism as defined in claim 2 wherein: V

(a) said probe is formed with a central passage therethrough; and,

(b) said-actuating means extends through said passage and engages oneend of said probe.

4. An installation mechanism as defined in claim 2 wherein saidmechanism further includes at least one additional dog carried by saidhousing and longitudinally spaced from said first dog, said additionaldog being biased into continual sliding engagement with said conduit andadapted to positively engage said conduit when said mechanism is movedin a direction opposite to the direction said mechanism is beingpropelled to said conduit.

Reterences Cited by the Examiner UNITED STATES PATENTS CHARLES E.OCONNELL, Primary Examiner.

C. D. JOHNSON, R. E. FAVREAU, Assistant Examiners.

UNITED STATES PATENT OFFICE CERTIFICATE: OF CORRECTION Patent No3,308,880 March 14, 1967 Edward D, Yetman error appears in the abovenumbered pat- It is hereby certified that t the said Letters Patentshould read as ent requiring correction and the corrected below.

line 16, after "receiving" insert position Column 15,

ies of such tool receiving within a conduit having a ser Signed andsealed this 7th day of November 1967:,

(SEAL) Attest:

EDWARD J. BRENNER Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer

1. A SYSTEM FOR INSTALLING A TOOL IN A PRESELECTED TOOL RECEIVINGPOSITIONS FORMED THEREIN AT LONGITUDINALLY SPACED LOCATIONS, COMPRISING:(A) IDENTICAL SHORT INDEXING AREA S LOCATED WITHIN THE CONDUIT ADJACENTSAID POSITIONS, SAID AREAS HAVING AN INTERNAL DIAMETER LESS THAN THEINTERNAL DIAMETER OF THE CONDUIT; (B) A CARRIER OPERATIVELY ENGAGING THETOOL AND ADAPTED TO PROPEL SAID TOOL THROUGH THE CONDUIT; (C) ASELECTIVELY OPERABLE INSTALLATION MECHANISM SECURED TO THE TOOL ANDADAPTED TO BE ACTIVATED TO INSTALL SAID TOOL IN SAID PRESELECTEDPOSITION; (D) AN INDEXING DEVICE OPERATIVELY SECURED TO SAIDINSTALLATION MECHANISM; (E) SENSING MEANS CARRIED BY SAID INDEXINGDEVICE AND COOPERABLE WITH SAID INDEXING AREAS TO SENSE THE NUMBER OFSAID AREAS THROUGH WHICH THE DEVICE HAS PASSED; AND, (F) ACTUATING MEANSCARRIED BY SAID INDEXING DEVICE AND COOPERATING WITH SAID SENSING MEANSTO ACTIVATE